The present invention relates to x-ray targets. X-ray devices of all types require a cathode and an x-ray target, which serves as an anode. A voltage is connected across the cathode and the x-ray target to create a potential difference between the cathode and the x-ray target. Electrons emitted by the cathode are accelerated across the potential and collide with the x-ray target so as to produce x-rays.
The x-ray target must be able to withstand strenuous high temperature operating conditions. The x-ray generation process, generally described above, causes the x-ray target to reach operating temperatures as high as several thousand degrees Celsius. Thus, the x-ray target must be constructed from materials that can withstand x-ray system operating temperatures. X-ray targets are also designed with materials to facilitate heat conduction away from a target track.
The x-ray operating temperature requirements lead to a multiple material x-ray target design. First, a substrate is provided that is made from a material that is relatively resistant to heat conduction. Second, a target core is attached to the substrate. The target core is made from a material with high heat conductivity. Finally, a target track is attached to the target core to complete the x-ray target. The target track is made from a material that can withstand the high temperature x-ray operating conditions located at the point where electrons emitted from the cathode collide with the x-ray target.
X-ray targets of the aforementioned construction present durability problems. Specifically, x-ray targets have a tendency to fail at the bond between the target core and the substrate.